Among them are Melbourne’s Dale and Trudi Tindal, who claim they're in the red after paying $6020 to Bestjet before it went bust.

The Tindals say they have been left in the red after booking flights through Bestjet. (Supplied)

In October, the couple booked four return flights to Greece through Bestjet.

It was supposed to be a trip of a lifetime. Not only would they celebrate Mr Tindal’s 50th birthday, but it was a chance for the couple’s 19-year-old son Hamish - who has an intellectual disability, MSL3 syndrome and uses a wheelchair - to see the Greek Islands.

Bestjet’s website went offline and calls to its landlines are left unanswered.

After multiple calls and emails from 9News, Pilot Partners today released a statement with advice for Bestjet customers who claim they are owed money.

If you booked a flight through Bestjet and received a flight ticket, Pilot Partners recommends you contact the airline to confirm your booking.

If you booked through Bestjet but have not received a ticket, contact the airline.

Budget airfare company Bestjet has collapsed. (Supplied)

If the airline says your ticket has been cancelled or is not confirmed, Pilot Partners recommends you contact your financial institution or travel insurance provider and request a refund for your flight.

Pilot Partners says if your financial institution or insurer will not refund you the amount, you may rank as an unsecured creditor of Bestjet by completing the Proof of Debt or claim form along with supporting documentation and emailing it to bestjetgroup@pilotpartners.com.au.

In addition, you may also wish to contact the consumer affairs agency in your state or the ACCC.

What you may have missed

Dozens of angry Bestjet customers have come forward with serious allegations about their experiences with Bestjet.

They have accused the company of not paying refunds, failing to issue tickets, sending invalid ticket confirmations, and not returning calls or emails.

Bestjet was sold to the McVicker Investment Group just six weeks ago.

“Representations made to the company failed to materialise and, unfortunately, we have been left with no choice but to place the business into voluntary administration to determine the best course of action for customers and suppliers, and to see whether Bestjet can continue to trade,” Bestjet director Robert McVicker Jr said in a statement.

McVicker Investment Group have refused multiple interview requests, with a PR agent representing them saying: “(The) McVicker(s) have decided not to comment on the customer claims for the time being, given that the Administrator is in control of the business including handling queries from customers.”

Bestjet Travel was founded by Rachel James, the wife of disgraced former Air Australia boss Michael James, just weeks after the airline’s collapse in 2012.

Air Australia was $97 million in debt when it went into voluntary administration, with Mr James disqualified by ASIC from managing corporations for three years.

The Australian Federation of Travel Agents stripped Bestjet of its industry accreditation more than 18 months ago.

This meant Bestjet was banned from using the 'ATAS - travel accredited' branding, a symbol of quality and professionalism.